St. Regis Container Corporation Mill Division--Coshocton 1 A

Transcription

1 CODE LETTERS FOR PROGRESS REPORT 93 CONTINUOUS EVALUATION OF CORRUGATING MEDIUM, FEBRUARY, 962 MachinS Codo Company - ill No, Lottor The Chesapeake Corporation--West Point - Continental Can Company, Inc.--Hopmwell K -Hedge V Crown Zellerbach Corporation-Baltimore I -- Baltimoro 2 D -- Bogalusa 4 -Labanon 2 P International Paper Company--Arecibo F G -- Bastrop Bastrop 2 B = Georgetnoi S The Mead Corporation--Harriman F -- Knoxville U -Lynehburg 2 J o-sylva St. Regis Container Corporation Mill Division--Coshocton A North Carolina Pulp Company--Plymouth Weyerhaeuser Company, North Carolina Div. 3 L.Olin Mathieson Chemical Corporation--Nonroe --Monroe 2 -o Owens-Illinois Glass Company--Tomahawk C -- Tomahawk 2 R -- Tomahawk 3 N -Big Island 3 H St. Joe Paper Company--Port St. Joe E Union Bag-Camp Paper Corporation--Savannah 2 M West Virginia Pulp and Paper Company-Covington 6 Q --Covington 7 -o -- Charleston -- Packaging Corporation of Americao-Filer City WI --Filor City 2 T

2 THE INSTITUTE OF PAPER CHEMISTRY Appleton, Wisconsin CONTINUOUS EVALUATION OF CORRUGATING MEDIUM Project 8-7 Report 93 A Progress Report to FOURDRINIER KRAFT BOARD INSTITUTE, INC. February, 962

3 TABLE OF CONTENTS Page INTRODUCTION NUMBER OF ROLLS OF CORRUGATING MEDIUM SUBMITTED FOR EVALUATION FROM EACH MACHINE 2 SUMMARY OF CURRENT MACHINE AVERAGES 4 GRAPHICAL PRESENTATIONS 5, 6 SUMMARY OF TEST RESULTS FOR INDIVIDUAL MACHINES 8-3 DISCUSSION OF RESULTS 3 INSTITUTE AND MILL CONCORA FLAT CRUSH TEST RESULTS 33-35

4 THE INSTITUTE OF PAPER CHEMISTRY Appleton, Wisconsin CONTINUOUS EVALUATION OF CORRUGATING MEDIUM * INTRODUCTION As requested by the Technical Committee of the Fourdrinier Kraft Board Institute, Inc., the reports pertinent to the continuous evaluation of corrugating medium are now being prepared by The Institute of Paper Chemistry on a bimonthly basis instead of the previous monthly basis. This new system was initiated on August, 96. This third report under the new system presents results obtained during the months of December, 96, and January, 962. In the two previous reports prepared on the bimonthly basis, the results for the two months covered by the respective reports were summarized for each month on an individual basis; that is, test averages were presented for each month. In the present report, at the request of the Technical Committee, the test averages are based on combined data for the two months covered by the report. During this third bimonthly period, 5 rolls of corrugating medium representing the production of twenty-three machines were evaluated. A tabulation of the number of rolls submitted from each machine during the months of December, 96, and January, 962, is given in Table I. In connection with the data given in Table I, it should be mentioned that, effective September, 96, at the request of the Technical Committee, the limit on the number of rolls submitted for evaluation from each machine during a given month was reduced from six to four. Each sample of corrugating medium was evaluated for basis weight, caliper, Concora flat crush (conditioned after fluting), H. and D. flat crush on singlefaced board, and runnability. Runnability was measured by corrugating each roll under standardized conditions on the Institute's corrugator into A-flute board at 6 feet per minute with minimum tension. If unsatisfactory runnability occurred

5 Page 2 Report 93.Fourdrinier Kraft Board Institute, Inc. Project 8-7 TABLE I NUMBER OF ROLLS OF CORRUGATING MEDIUM SUBMITTED FOR EVALUATION FROM EACH MACHINE December, 96, and January, 962 Machine Code Number of Rolls A B C D E F G H I J K L M N P Q R S T U V W Total 5 a Some of these rolls arrived too late for inclusion in the previous report.

6 Fourdrinier Kraft Board Institute, Inc. Page 3 Project 8-7 Report-93 at this speed, the corrugator was slowed down in increments of 25 f.p.m. until satisfactory runnability was obtained--ie., no ruptured flutes. If the medium fabricated satisfactorily at 6 f.p.m. with minimum tension, further runs were made at higher tensions to determine when cracking occurred. The higher tensions used were.5 lb. per inch,. lb. per inch, and.5 lb. per inch. Flat crush was determined on the single-faced board obtained at a speed of 6 f.p.m. with minimum tension. The flat crush results, in addition to supplying information about quality, will provide data which may be useful in studying the relationship between Concora flat crush and combined board flat crush for each participant's medium. The average test results obtained on the rolls of corrugating medium submitted by each participant during December, 96, and January, 962 (current machine average) are shown in Table II and graphically presented in Fig. to 4. In addition to a comparison of the test data obtained for the various machines, Table II also presents the current F.K.I. averages, cumulative F.K.I. averages, and the F.K.I. indexes. The current F.K.I. average is the average of test results for all machines participating in the study during a given period..the cumulative F.K.I. average is based on the results for the previous twelve-month period excluding the result for the current period. The F.K.I. index is obtained as follows: current FoK.I. average cumulative F.K.I. average The F.K.I, index provides a ready means of comparing the current quality with previous results. An index greater than % indicates that current quality is higher than the average result for the previous twelve periods; an index below % indicates that current quality is lower than the average result for the previous twelve periods.

7 w M \. o o a I-'- cho H (D flj td HO Co H I dr -F TABLE II SUMMARY OF CURRENT MACHINE AVERAGES December, 96 and January, :962 Mill Code Basis Weight, lb. p.s.i. Single-Face Flat Crush, p.s.i. A B C D E F G H I J K L M N P Q.R S T U V W , Current F.K.I. Average Cumulative F.K.I. Average F.K.I. Index, %

8 Fourdrinier Kraft Board Institute, Inc. Project 8-7 Page 5 Report r 28 - a F.K.i. -Av. U - 26 Z- Mach. A B C D E F G H I J Figure. Comparison of Basis Weight Results VW r r. F.K.., Av. a. Qo- 3 I nl ni J 9 Current machine average ---- Cumulative machine average Figure 2. Comparison of Caliper Results

9 Page 6 Report 93 Fourarinier Kraft Board Institute, Inc. Project , I- Oi~ C-) z C-) 34 U, " i-- Fl I I H - F -- JT-flI-H - tt - t t trtl [ I. I, - Av. U) J %J I 38 Mach. AB8C.D Figure 5.' Comparison 'of Concora Flat Crush"Results' T U VW I- C-) a: 3d -J. F.K.. U) Mach.A BC DE F GH I J ~~Current machine averagei Cumulative machine average Figure 4. Comparison of.single-face Flat Crush Results

10 Fourdrinier Kraft Board Institute, Inc. Page 7.Project 8-7 Report 93 The test results obtained on the sample lots submitted from the production of individual machines during December, 96, and January, 962, are shown in Tables III through XXV for Machines A through W, respectively. The maximum, minimum, and average test results obtained on each sample lot are shown for all tests except basis weight for which only the average is shown; in addition the over-all average result for all sample lots submitted from a given machine is shown for each test. The latter over-all averages are reported as "current machine averages." A cumulative machine average is also shown and is calculated by averaging the current machine average for the previous twelve periods (excluding the current period). Also shown for each machine in Tables III to XXV are the machine factor and machine index which are defined as follows: current machine averagemachine. factor x = machine factor (%) cumulative machine average current machine averagemachine ind.. x = machine index (%) cumulative F.K.I. average The machine factor and machine index provide a means for comparing the current machine average with either the previous results for that particular machine or with the cumulative results for all machines--ioe., the cumulative F.K.I. average.

11 (D Xn w q (D E - kc - H- Pb C H -o Cal c td ' ' O O POF C H - l- I TABLE III SUMMARY OF TEST RESULTS FOR MACHINE A December, 96 and January, 962 Code Made Mill Roll Received No. Basis Weight, lb. per sq. ft. Max. Min. p.s.i. Av. Runnability, maximum Single-Face IFlat Crush, p.s..i. 6 f.p.m., lb./in. A A Cumulative Machine Average

12 :.. ceto (D P --~j oti o HY-b c-t Cd 9) CD I-I rsj et cd Dft *^ C TABLE IV SUMMARY OF TEST RESULTS FOR MACHINE B December, 96 and January, 962 Mill Roll Code Made Received No. Basis Weight, lb. per sq. ft. Max. Min. Av. p.s.i. Runnability, maximum Single-Face Flat Crush, p.s.i. 6 f.p.m., lb./in. B-l B-2 B-3 B-4 B Cumulative Machine Average o

13 Runnability, maximum 6 f.p.m., lb./in. (D h \-A o or p. H- o H- cp (D i-b c+ Ft P-i Ho c O H -I <H - TABLE V SUMMARY OF TEST RESULTS FOR MACHINE C December, 96 and January, 962 Code Made Mill Roll Received No. Basis Weight, lb. per sq. ft. Max. -Min. Av. p.s.i. Single-Face Flat Crush, p.s.i. C-l c-2 C-3 c-4 C-5 c-6 C-7 C Cumulative Machine Average

14 Runnability, mxlajt nn 6 f.p.m.., lb. /in. -_2 o (D. P, H P. H-(D l '- C t ~!d (D ', Id -d P i Gq ci- 'M I. & H. - t- TABLE VI SUMMARY OF TEST RESULTS FOR MA.CBNE D December, 96 and January, 962 Mill RollI Code Made Received No. Basis Weight, lb. per sq. ft. Max. Min. Av. Concora Flat Crash, p.s.i. Single-Face Flat Crush, p.s.i. D~- D-2 D-3 D-.4 D-5 D-6 D-7 D-8-2-lli-6 2P -ll ll4 ll5 ii6 7 8 l ll ll ll o 36.o I 43.o Current Machine Ave rag6 C~umuative Machine Average 28.2P 28.o

15 Runnability, 6 f.p.m., lb. /in. W U-d (D P) O (D '- I\J r-i I-b Ft PI- ~I- ~Ii C-f- td- -dho TABIE VII SUMMARY OF TE~ST RESULTS TYJR MPACEM E December, 96 and January, 962 Code Made E- E-2 E-3 E-4 E-5 E-6-27~-6 * ll-27-6 * l-27' MillI Roll Received No. 2-ll-6 2P-lli i 2-l Cumulative.Machine Average Machine.Index, lo Basis Weight, lb. per sq. ft Single -Face Flat p.s.i. Crush, p.s.i. 36.o 36.o

16 Runnability, Tmax!MT 6 f.p.m., lb./in.' (D P, H p- ~ I-I CH H Cn (D -d -d w i-l OQ & (D TABLE VITT SUI~MAFR OF TEST RESULTS FOR MA.CHIE F December, 96 and January, 962 Code Made Mill Roll Received No. Basis Weight, lb. per sq. ft. Max. Min. Av. P.S. i. Max. MI. Av. Single -Face Flat Crush, p.s.i.. Max. Min Av. F- F-2 F-3 F-4 F-5 F-6 F-7 F-8 i-6-6 i-6-6 2P IP I ' ui o P Cumulative Machine Average o

17 Runnability, maximum 6 f.p.m., lb./in. Min. /2 /2 (D X O (D CF. H -I O cl-h (D I-i PH (t OF - H c- O - CO - - TABLE IX SUMMARY OF TEST RESULTS FOR MACHINE G December, 96 and January, 962 Code. Made Mill Basis Weight, Roll lb. per Received No. sq. ft. Max. Min. Av. p.s.i. Single-Face Flat Crush, p.s.i. G-l G-2 G-3 G-4 G-5 G-6 G-7 G-8 G r '-i Cumulative Machine Average ioo

18 Runnability, maximum 6 f.p.m., lb./in. /2 o o. C-. (D c+ H- o 3 F I-i c+i- P+ PD H. P (D Oj c+ (D \ H OJ \-f TABLE X SUMMARY OF TEST RESULTS FOR MACHINE H December, 96 and January, 962 Code Made Mill Roll Received No. Basis Weight, lb. per sq. ft. Max. Min. Av. p.s.i. Single-Face Flat Crush, p.s.i. H- H-2 H-3 H-4 H-5 H-6 H-7 H-8 H-9 H- H-ll H P Cumulative Machine Average

19 Runnability, maxitmum 6 f.p.m., lb. /in. (D 9) Or(D C± H a" \UO I-i PIc2 HCD Co TABLE XI SUMM4ARY OF TEST RESULTS FOR MACHIN~E I December, 96 and January, 962 Code Made Mill Basis Weight, Roll lb. per Received No. sq. ft. Max. Min. Av. p.s.i. Single-Face Flat Crush, p.s.i. I-2 I-3 I- 4 I-5 ' I llo ill lip 3 4 ll o Cumulative Machine Average o ll

20 Runnability, 6 f.p.m., lb./in. H(D P H) I- F- IC'- (D (D CDF P-I a) c-f - d H TABLE XII SUMMARY OF TEST RESULTfS FOR MACHINE J December, 96 and January, 962 Code Made MillI Basis Weight, Roll lb. per Received No. sq. ft. Max. Min. Av. p.s.i. Single-Face Flat Crush, p.s.i. J- J-2 J-3 J-4] J- 5 j-6 J-7 j ll-24~ i-62-4i o-62 -o i i. 8 42, o..2 h 36.o 36.o 33. 3k Cumulative Machine Average

21 Runnability, maximum 6 f.p.m., lb./in.. (D) P (D co LA o p- i-i H- (D o c> PH H cdhn o. cf c+ O H M - TABLE XIII SUMMARY OF TEST RESULTS FOR MACHINE K December, 96 and January, 962 Code Made Mill - Roll Received No. Basis Weight, lb. per sq. ft. p.s.i. Single-Face Flat Crush, p.s.i. K-l K-2.K-3 K-4 K-5 K-6 K-7 K Cumulative Machine Average

22 Runnability, maximum 6 f.p.m., lb./in. /2 :d t of o a (D of o c+ H P- I-,. HP. t- (,~ I c-- t -b c+ P- (-) H. r_ (D P c+ (D \ I-' w SDC TABLE XIV SUMMARY OF TEST RESULTS FOR MACHINE L December, 96 and January, 962 Code Made Mill Roll Received No. Basis Weight, lb. per sq. ft. p.s.i. Single-Face Flat Crush, p.s.i. L- L-2 L-3 L-4 L-5 L-6 L-7 L Cumulative Machine Average

23 Runnability, maxdmum 6 ff.p.m., lb. /in.. (D P) (D wa I-i ( F-I P-I '-I H'. D coi- H TABLE XV SUMMARY OF TEST RESULTS FOR MACHIN~E M December, 96 and January, 962 Code Made Mill Basis Weight, Roll lb. per Received No. sq. ft. max. Min Av. p.s. i. Max. Min Av. Single-Face Flat Crush, p.s.i. M- M-2 M-3 M- 4. M- 5 m-6 M-7 m-8 ll-25-6 ll ii-6.2-ill o o P P o i o Cumu~lative. Machine Average '

24 Runnability, maximum 6 f.p.m., lb. /in. H(D P P(D) (D C+ Ct( \DfOR TABLE XVI SUMMARY OF TET RESULT'S FOR MACHINE N December, 96 and January, 962. Code Made Mil I Roll Received No. B.sis Weight, lb. per sq. ft. CaliperI p.s.i. Single-Face Flat Crush-, p.s.i. N-i N-2 N-3 N-4 N- 5 N-6 N * i o o P Cumulative Machine Average

25 Runnability, maximum 6 f.p.m., lb./in. (D J ud Uj ro PI ( (D Pa 'dh " H ( cj. ct cf rgo CO H --I TABLE XVII SUMMARY OF TEST RESULTS FOR MACHINE December, 96 and January, 962 Code Made Mill Roll Received No. Basis Weight, lb. per sq.-ft. p.s.i. Single-Face Flat Crush, p.s.i Cumulative Machine Average

26 Runnability, MaXi~mum 6 f.p.m., lb./in. C-,. (D P H (D co (Df Ft PI- C t (Df I) P d- (D \k R W LO TABLE XVIII SUMMARY OF TEST RESULTS FOR MACHfl'E P December, 96 and January,. 962 Code Made MillI RollI Received No. Basis Weight, lb. per sq. fft. max. Min Av. P.S.i. Single-Face Flat Crush, p.s.i. max. Min. Av. P- P-2 P-3 P- 4 P-5 P-7 lli-9-6 i-9-6 i K-3 K- 4 K- 5 K-6 L_8 L-9 L- L-ll ll ll P P o Cumulative Machine Average

27 /2 /2 /2 /2 (Do) ot O (D F- UO w ' (D cf o O CD c+ -b CO H --I D P. CO ~sl TABLE XIX SUMMARY OF TEST RESULTS FOR MACHINE Q December, 96 and January, 962 Code Made Mill Roll Received No. Basis Weight, lb. per sq. ft. p.s.i. Single-Face Flat Crush, p.s.i. Runnability, maximum 6 f.p.m., lb. /in. Q-. Q-2 Q-3 Q-4 Q-5 Q-6. Q-7 Q I Cumulative Machine Average o

28 o r. c- H* ', H (D I-i Cl c+ I-H PC p- P. o- - c+ ( W k-n TABLE XX SUMMARY OF TEST RESULTS FOR MACHINE R December, 96 and January, 962 Code Made Mill Roll Received No. Basis Weight, lb. per sq. ft. p.s.i. Single-Face Flat Crush, p.s.i. Runnability, maximum 6 f.p.m., lb./in. R-l R-2 R-3 R-4 R-5 R-6 R-7 R Cumulative Machine Average

29 Runnability, OC(D i-i C± R) r_ r-f- I-i DH. HCD H'- Il HO TABLE XX~I SUMMARY OF TEST RESULTS FOR MACHIN~E S December, 96 and January, 962 Code Made Mml I Rol I Received No. Basis Weight, lb. per sq. ft. p.s.i. Max. Mmn. Av. Single-Face Flat Crush, p.s.i. 6 f.p.m., lb. /in. S-i I-25-6 S-2 2p-6-6 s P4i o 27.2P ? o Cumulative Machine Average

30 Runnability, maximum 6 f.p.m., lb. /in. F -jo d- Hj H(D P HI-i CD F OD -)d 9) NfC TABLE XOXII SUMMARY OF TEST REEULTS FOR MACHIN~E T December, 96 and January, 962 Code Made RollI Received 'No. Basis Weight, lb. per sq. ft. Concc Max. Min Av. Max. )ra Flat Crush, p.s.i. Min. Av. Single-Face Flat Crush, p.s.i..max. Mm. Av. T T T o Cumulative Machine Average

31 Runnability, maximum 6 f.p.m., lb./in. Id Oq cto+ o U o PI -i t. c+ cn CO'. O H (D he O H H O -I. Oc TABLE XXIII SUMMARY OF TEST RESULTS FOR MACHINE U December, 96 and January, 962 Code Made Mill Roll Received No. Basis Weight, lb. per sq. ft. Max. Min. Av. p.s.i. Single-Face Flat Crush, p.s.i. U-l U-2 U-3 U Cumulative Machine Average

32 SUMMAY OF TEST RESULTS FOR MACHINFE V C-s. j (D P, December, 96 and January, 962 P Runnability, maxitmum 6 f.p.m., lb. /in. HPH H CD CD ci-~ H Cl) ci -Cd \ ) U"kO Code Made MillI RollI Received No. Basis Weight, lb. per sq.-ft. CaliJper, max. Min Av. p.s.i. max. Min. Av. Single-Face Flat Crush, p. s.i. Max. Min Av. C+ H. C) v- V-2 V-3 v i ' :_ P i P Cumulative Machine Average UO

33 Runnability, 6 f.p.m., lb./in. (D P UJ ( r_ PI- :I- DH. H D col-i -HO TABLE XXCV SUMMARY OF TEST RESULTS FOR MACHINE W December, 96 and January, 962 Code Made MillI RollI Received No. Basis Weight, lb. per sq. ft. p.s. i. Single-Face Flat Crush, p.s.i. W-l. W-2-4i-6p W i Cumulative Machinhe Average

34 Fourdrinier Kraft Board Institute, Inc. Project 8-7 Page 3 Report 93 DISCUSSION OF RESULTS Shown below from Table II are the maximum and minimum current machine averages noted for each test during the current period (December, 96, and January, 962); the current machine average is the average of the results obtained on all rolls submitted from a given machine during the current period. Also given for each test is the current F.K.I. average which is determined by averaging the current machine averages for a given period and is indicative of the test level being maintained by the industry as a whole to the extent that the industry is represented by the participating machines: Maximum Current Machine Average Minimum Current Machine Average Current F.K.I. Average Basis wt., lb pt Concora flat crush, p.s.i Single-face flat crush, p.s.i The runnability data for the 5 rolls evaluated during December, 96, and January, 962, are summarized as follows: Runnability Less than 6 f.p.m. with minimum tension 6 f.p.m.--minimum tension 6 f.p.m.--/2 lb. per in. tension 6 f.p.m.--l lb. per in. tension 6 f.p.m.-- lb. per in. tension Number of Rolls 8, 7, 24 Percentage of Total Rolls

35 Page 32 Fourdrinier Kraft Board Institute, Inc. Report 93. Project 8-7 In Table XXVI a comparison of Institute and mill Concora flat crush test results obtained on conditioned specimens is given for each machine for the current period. These comparisons permit interested participants to submit their Concora flat crush test results to The Institute of Paper Chemistry so that comparative results may be included in the monthly reports. Data sheets for supplying this information may be obtained from the Institute. Comparisons of this kind are a helpful adjunct to other calibration procedures. Shown in Table XXVI are the Institute and mill Concora averages for each roll included in these comparisons, the difference between the roll average based on Institute data and that based on mill data, the Institute and mill averages based on all rolls included in the comparison, and the difference between these over-all averages. The Concora flat crush data shown in Table XXVI are summarized in Part I of Table XXVII where for each machine the following information is given: () Current machine average based on Institute data, (2) current machine average based on mill data, (3) the average difference--that is, the difference between the current machine average based on Institute data and that based on mill data and (4) the maximum difference encountered in comparing Institute and mill test averages for individual rolls. In Part II of Table XXVII the average differences given in Part I have been converted to per cent. Comparative data from the previous bimonthly report are also included in Part II of Table XXVIIo It may be seen in Part II of Table XXVII that, for the current period, the highest average difference of 8.3% was associated with Machine E and the lowest of.5% with Machines C and R. In Table XXVIII a comparison of the agreement between Institute and mill Concora flat crush data is given for the current period; Comparative data for the months of October and November, 96, are also included. The data shown for the

36 -d C- a (Do cl. -- H H PH (D OY O Pi Fb (D H c- c+- d- (D H. cf (D \d \,\J4 TABLE XXVI INSTITUTE AND MILL CONCORA FLAT CRUSH TEST RESULTS ON INDIVIDUAL ROLLS FOR DECEMBER, 96 AND JANUARY, 962 Machine B Mill p.s.i. Roll Insti- Differ- Code No. Made tute Mill ence B B B i B B Current Machine Av Machine C Mill p.s.i. Roll Insti- Differa Code No. Made tute Mill ence C C C C C C C C Current Machine Av Machine D Mill p.s.i. Roll Insti- Differ- Code No. Made tute Mill ence D D D D Current Machine Av Machine E E-l E E E E E Current Machine Av Machine H Machine F F F F F F F F F Current Machine Av Machine I Machine G G G G G G G G G G Current Machine Av Machine J H- H-2 H-3 H-4 H-5 H-6 H-7 H-8 H-9 H- H-ll H I I I I J- J-2 J-3 J-4 J-5 J-6 J-7 J Current Machine Av Current Machine Av Current Machine Av athis difference is the amount in p.s.i. units by which the mill result is higher or lower than the Institute result.

37 (D P O D \k +- H- H- (D -+ C-C P-i bi -d H o ch i-. HO F- --- AM TABLE XXVI (Continued) INSTITUTE AND MILL CONCORA FLAT CRUSH TEST RESULTS ON INDIVIDUAL ROLLS FOR DECEMBER, 96 AND JANUARY, 962 Machine K Mill p.s.i. Roll Insti- Differ- Code No. Made tute Mill ence K K K K K K K Current Machine Av. 39.i Machine L Mill p.s.i. Roll Insti- Differ- Code No. Made tute Mill ence L-l 59 l L L L L L L L Current Machine Av Machine M Mill p.s.i. Roll Insti- Differ- Code No. Made tute Mill ence M M M M M M M M Current Machine Av Machine N N N N N N N N Current Machine Av Machine Current Machine Av o.8 Machine Q Q Q Q Q Q Q Q Current Machine Av Machine R Machine S Machine T R R R R R R R R S S S T- i T T Current Machine Av Current Machine Av Current Machine Av Machine U U U U U Current Machine Av Machine W W W W Current Machine Av athis difference is the amount in p.s.i. units by which the mill result is higher or lover than the Institute result.

38 o o c c H fd PL c+ H- OHD (D o (DHC+?P. O X G W \ O \- \n TABLE XXVII PART I: A COMPARATIVE SUMMARY FOR EACH MACHINE OF THE CONCORA FLAT CRUSH AVERAGES BASED ON INSTITUTE DATA AND THOSE BASED ON MILL DATA Machine Code Number of Rolls Compared A B C D E F G H I J K L M N P Q R S T U V W p.s.i. Current Machine Av. (Institute)a Current Machine Av. (Mill) Average Differenceb Maximum Difference c PART II: A TABUIATION FOR EACH MACHINE OF THE AVERAGE DIFFERENCE (PER CENT) BETWEEN TEE CONCORA FLAT CRUSH BASED ON INSTITUTE DATA AND THAT BASED ON MILL DATA Average Difference, %d Current Report (Dec. and Jan.) 92nd Report (Nov.) 92nd Report (Oct.) o a Comparisons based on current machine average include only those rolls for which mill data were submitted. baverage difference is the difference between the current machine average based on Institute test results and that based on mill test results with the Institute test results used as the reference. See Table XXVI. c Maximum difference is the greatest difference encountered in comparing Institute and mill test averages for individual rolls. See Table XXVI. daverage difference ( per cent) is computed by dividing the average difference in p.s.i. (shown above in Part I of this table) by the Institute current machine average and multiplying the result by.

39 Page 36 Report 93. F6urdrinier Kraft Board Institute, Inc. Project 8-7 current period indicate that a substantial improvement in agreement between Institute and mill Concora data is evident over that shown for the months of October and November. Some of the factors that may have contributed toward the relatively poor agreement between Institute and mill Concora data in October and November were discussed in the previous report. TABLE XXVIII COMPARISON BY PERIODS OF AGREEMENT BETWEEN INSTITUTE AND MILL CONCORA FLAT CRUSH DATA Average Percentage Difference Between Institute and Mill Concora Flat Crush Test Resultsa. ' -, O Percentage of All Machines Included Within the Indicated Range Current October November Periodb o d.. a The average obtained at the Institute was used as the reference in the calculation of the percentage differences. b December, 96, and January, 962. c Maximum percentage difference was.6. d Maximum percentage difference was 8.3. THE INSTITUTE OF PAPER CHEMISTRY W. N. Hubert, Research Aide Container Section R. C. McKee, Chief, Container Section